Control device



OCL 22, 1940. I p s RUSSEL 2,218,975

CONTROL DEVI CE Filed March 8, 1939 JNEL lNVENTOR W M @M/CM AQATTORNEY Patented Oct. 22, 19403 UNITED STATES CONTROL DEVICE Philip S. Russel, Detroit, Mich assignor to Detroit Lubricator Company, Detroit, Mich, a corporation of Michigan Application March 8, 1939, Serial No. 260,606

12 Claims. (Cl. 200138) My invention relates to new and useful improvements in temperature responsive control devices.

An object of my invention is to provide a con- 5 trol device having a plurality of control elements operable in predetermined constant relation with respect to each other.

Another object is to provide a temperature responsive control device having a plurality of movable control elements operable at a constant differential of temperature irrespective of change in the range of operation of one of said elements.

The invention consists in the improved construction and combination of parts, to be more 1.3 fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of this specification, I have fully and clear- 20 1y illustrated a preferred embodiment of my invention, in which drawing- Figure 1 is a view in perspective of a control device embodying my invention and shown in cooperative relation to a diagrammatically illus- 25 trated control system, and

Fig. 2 is a detail top plan view of the control device.

Referring to the drawing by characters of reference, l designates a supporting base member 30 of electric insulating material havinga pair of laterally spaced supporting bracket members 2, 3 rigidly secured thereto. The bracket member 2 has a contact member 4 adiustably screw-threaded therethrough and also carries a U-shaped 35 permanent magnet 5 adjacent the contact member 4 and with its poles extending substantially parallel thereto. The bracket 3 has a contact member 6 adjustably screw-threaded therethrough and also carries a U-shaped permanent 40 magnet 1 having its poles extending substantially parallel to the contact member 6. Supported on the base member I and having one end rigidly secured thereto, as at 8, there is a temperature responsive operating member 9, preferably a strip 45 of bimetal, which carries adjacent its free end a control element or contact member l cooperable with and movable into engagement with the contact member 4 which is fixed during normal operation. Also carried by and movable with the 0 strip 9 is an armature member ll, preferably of soft iron, cooperable with the poles of magnet which has its pole faces adjusted with respect to contact 4 such that upon engagement of contacts 4 and I0 an air gap will be left between the pole faces and the armature ll. Secured to the base member I there is a bracket 12 carrying an adjustable abutment member I3 engageable with the face of bimetal strip 9 adjacent its fixed end so that the extent of flexing of the strip 9 upon temperature change which will move contact 5 member l0 into engagement with contact member 4, and therefore the range of operation, can be regulated. Positioned beside and in edge to edge relation to th strip 3, there is a spring blade member l4, preferably of bronze, having one end rigidly secured to the base member I, as at l5, and extending longitudinally of and substantially parallel to the strip 9. At its free end the member l4 carries a control element or contact member l6 cooperable with the contact member 6 which 15 is fixed during normal operation. Adjacent the contact member I 6 there is an armature IT, also secured to member l4 and preferably of soft iron, for cooperation with the end faces of the poles of magnet l. The magnet I is so adjusted relative to contact member 6 that when contact members 6 and I6 are in engagement, there will be an air gap between the pole faces of the magnet and the armature l1. Movement 01' strip 9 in response to temperature chan e is transmitted to the blade member l4 by a strip or bar of electric insulating material H! which bridges the space between members 3 and I4 and which is secured at one end to one of said members and at its other end to the other of said members.

In operation, the control device may be connected in circuit with a pair of control means 19 and 20, which are shown as electrically heated, bimetal operators for actuating any desired means to be controlled. For purposes of illustration, the control means resistance elements 2| and 22 are shown as supplied with electric energy from the secondary of the transformer 23 and positioned in lead wires 24, 25 respectively, which are connected to the blade member l4 and the bimetal strip 9 respectively. The other side of the transformer secondary is connected by lead wires 26, 21 to the contact members 4 and 6 respectively. The contact member 6 is adjusted relative to contact member 4 in accordance with the desired operation of the control means l9 and 20.

Thus, if it is desired to have the control means l9 and 2!) simultaneously energized, then contact member 6 will be positioned with respect to contact member 4 so that they will be simultaneously engaged by contact members l6 and [0 respectively. However, if it is desired to have the circuits to the control means l9 and 20 closed at a constant temperature differential, then the contact member 6 is moved forward with respect to contact member 4 so that contact member 6 will be engaged by contact member I6 prior to enagement of contact member H! with contact member 4. Assuming that the control device is set or adjusted in the above manner for a 2 F. differential of operation between closure of circuit at contact member 6 with respect to circuit closure at contact member 4 and with the adjustable abutment l3 positioning bimetal strip 9 so that a 70 F. temperature is required to sumcient- 1y fiex strip 9 to cause engagement of contact member to with contact member 4, with strip 9 moving to close circuit on temperature increase, then the operation will be as follows: As the temperature to which strip 9 is subjected approaches 68 F., the strip 9 will be moving toward contact member 4 and acting through the bridge bar or strip It will also be moving contact member 16 toward contact member 6 against the inherent resilience of the spring blade member l4. When the temperature of 68 F. is reached,

contact member it will engage contact member 6 and complete the circuit from the transformer through lead wires 21 and 24 to the resistance element 2|. As the temperature affecting strip 9 continues to increase, the strip will fiex further toward contact member 4 due to lost motion at spring blade member I4 and when a temperature of 70 F. is reached, contact member Ill will engage contact member 4 and complete the circuit from the transformer 23 through lead wires 26 and 25, thereby energizingthe resistance element 22. Assuming that the air gap of magnets 5 and l is set for the minimum magnetic pull on armatures l I and I1 respectively which are providing a good snap action or quick movement on breaking of circuit, then as the temperature to which strip 9 is subjected falls below 70 F., strip 9 will move quickly away from contact member 4 breaking circuit between contact members 4 and Hi to. deenergize resistance element 22. This breaking of circuit will, however, not afiect the circuit at contact members 6 and it due to the lost motion provided'by spring blade member i4.

I circuit is made between contact members 4' and i0 and between contact members 6 and I 6 upon drop of temperature to which the bimetal strip' is subjected.

What I claim and desire to secure by Letters Patent of the United States is:

1. A control device, comprising a supporting means, a control means having a movable element, a second control means having a movable element, a movable member carried by said supporting means and operable to move said firstnamed element, a temperature responsive member carried by said supporting means, said second-named element being carried by and operable to be moved by said responsive member, and means carried by and operable to transmit the movement of said responsive member to said movable member. 4

2. A control device, comprising a supporting means; a control element resiliently mounted on said supporting means, a temperature responsive' member spaced from said control element and mounted on said supporting means, a control element having a fixed portion and a movable portion, said movable portion being carried by said 5 responsive element and operable to be moved by said responsive member, said fixed portion being carried by said supporting means, means bridging the space between and operable to transmit move ment from said responsive member to said firstnamed element, and means for moving said fixed portion to-adjust the relative operation of said control elements.

. 3. A control device, comprising a supporting means, a spring blade member carried bysaid supporting means, a control element movable by said blade member, a bimetal strip member positioned beside of and extending longitudinally of and spaced from said blade. member, a control element movable by said strip member, means cooperable with said strip member to cause said last-named element to operate with a snap-action, and means bridging the space between and operable to transmit movement from said strip member to said blade member.

4. A control device, comprising a supporting means, a spring blade member carried by said supporting means, a control element movable by said blade member, a'bimetal strip member positioned in edge to edge relation with and extending longitudinally of and spaced'from said blade member, a control element movable by said strip member, means cooperable with said strip member to cause said last-named element to operate with a snap-action, and means bridging the space between and secured to one of said members and operable to transmit movementfrom said strip member to said blade member.

5. A thermostatic switch, comprising a supporting means, a pair of spaced contact members carried by said supporting means, a spring blade member mounted on said means, a contact member cooperable with one of said spacedcontact members and carried by said blade member, a bimetal strip member carriedby said supporting means and positioned in laterally spaced edge to edge relation to said blade member, a contact member cooperable with the other of said spaced contact members and carried by said strip'member, a strip of insulating material secured to said blade member and to said strip member to transmit movement .from said strip member to said blade member, and an adjustable abutment member carried by said supporting means and engageable with and for regulating the operation of said strip member.

6. A thermostatic switch, comprising a supporting means, a pairof spaced contact members carried by said supporting means, an elongated flexible strip member mounted on said means, a contact member cooperable with one of said spaced contact members and carried by said flexible member, a bimetal strip member carried by said supporting means and positioned in parallel spaced relation with said flexible member, a contact member cooperable with the other of said spaced contact members and carried by said bimetallic member, means cooperable with one of said strip members for moving said one strip member with a snap-action, and force transmitting means operatively connected to aid bimetallic member and to said flexible member to transmit movement from said bimetallic membe tosaid flexible member.

7. A thermostatic switch, comprisinga support= ing means, a pair of spaced contact members carried by said supporting means, an elongated flexible strip member mounted on said means, a contact member cooperable with one of said spaced contact members and carried by said flexible member, a bimetal strip member carried by said supporting means and positioned in parallel spaced relation with said flexible member, a contact member cooperable with the other of said spaced contact members and carried by said bimetallic member, force transmitting means operatively connected to said bimetallic member and to said flexible member to transmit movement from said bimetallic member to said flexible member, and adjustable means determining the tem perature at which said bimetallic member is operable to move said second-named carried contact member into engagement with said other contact member.

8. A thermostatic switch, comprising a supporting means, a pair of spaced contact members carried by said supportingmeans, an elongated flexible strip member mounted on said means, a contact member cooperable with one of said spaced contact members and carried by said flexible member, a bimetal strip member carried by said supporting means and positioned in parallel spaced relation with said flexible member, a contact member cooperable with the other of said spaced contact members and carried by said bimetallic member, force transmitting means 0peratively connected to said bimetallic. member and to said flexible member to transmit movement from said bimetallic member to said flexible member, and means for adjusting the relative engagement of said first-named carried contact member with said one contact member and of said second-named carried contact member with said other contact member.

9. A thermostatic switch, comprising a supporting means, a pair of spaced contact members carried by said supporting means, an elongated flexible strip membermounted on said means, a contact member cooperable with one of said spaced contact members and carried by said flexible member, a bimetal strip member carried by said supporting means and positioned in parallel spaced relation with said flexible member, a contact member cooperable with the other of said spaced contact members and carried by said bimetallic member, force transmitting means operatively connected to said bimetallic member and to said flexible member to transmit movement from said bimetallic member to said flexible member, and means for adjusting the position of said one contact member in respect to said other contact member thereby to determine the difference of temperature of said bimetallic member which will cause engagement of said first-named bimetallic member being operable upon temperature change to move said carried contact member into engagement with said one contact member, a resilient strip member carried by said supporting member and positioned adjacent saidbimetallic member, a contact member carried by said resilient member and cooperable with the other of said pair of contact members to control an electric circuit, and a connecting means carried by said bimetallic member and operatively connected to said resilient member, said bimetallic member being operable upon movement to act through said connecting means to move said resilient member thereby to move said secondnamed carried contact member into engagement with said other contact member.

11. A thermostatic switch, comprising a supporting means, a pair of spaced contact members carried by said supporting means, a spring blade member having one end portion supported from said supporting means, a contact member cooperable with one of said spaced contact members and carried by said blade member atits other end portion, a bimetal strip member having one end portion supported from said supporting means and positioned in laterally spaced edge to edge relation to said blade member, a contact member cooperable with the other of said spaced contact members and carried by said strip member at its other end portion, a strip oi. insulating material secured to said blade member adjacent said blade member other end portion and to said strip member adjacent said strip member other end portion to transmit movement from said member adjacent said strip member one end' portion and operable to regulate the operation of said strip member.

12. A thermostatic switch, comprising a supporting means, a pair oi. spaced contact members carried by said supporting means, a spring blade member having one end portion supported from said supporting means, a contact member cooperable with one 01' said spaced contact members and carried by said blade member at its other end portion, a bimetal strip member having one end portion supported from said supporting ,means and positioned in laterally spaced edge to edge relation to said blade member, a contact member cooperable with the other of said spaced contact members and carried by said strip member at its other end portion, a strip of insulating material secured to said blade member adjacent said blade member other end portion and to said strip member adjacent said strip member other end portion to transmit movement fmm said strip memberto said blade member, an adjustable abutment member carried by said supporting means and engageable with said strip member adjacent strip member one end portion and operable to regulate the operation of said strip member, and means for adjusting one of said contact members thereby to adjust the relative 6 engagement of said carried contact members with 

